1. Technical Field
The embodiments herein generally relate to microscopes and particularly to stereomicroscopes. The embodiments herein more particularly relate to stereomicroscopes with dual objectives with variable inter-objective distances to increase visual angle to increase 3-D effect.
2. Description of the Related Art
The working with magnifying glasses and microscopes generally limits a freedom of movement. With magnifying glasses, the distance from the object is fixed and in addition, there is a very limited field of vision. This is particularly detrimental in the medical & surgical field. Magnifying glasses, with their two-dimensional vision, are often low powered and not convenient to operate. Surgical microscopes having two eyepieces with variable and adjustable inter pupillary distances (IPD) exist in the market. Normally, the adjustment of the IPD facilitates a comfortable viewing with two eyes. These microscopes are referred to as stereomicroscopes.
The main difference between the conventional microscope and the stereomicroscope is that the conventional microscope is used to observe a sample from a single direction, while the stereoscopic type microscope is used to observe an object from two significantly different angles thereby providing the two distinctly differing images needed for a stereoscopic vision. The stereoscopic microscope gives a three-dimensional view of the object, while the same object appears flat when viewed through a conventional microscope. This holds true even if the compound microscope has a binocular head and eyepieces because each eye sees almost exactly the same image due to a single objective lens system.
Normally, stereomicroscopes provide a single objective lens system with a beam splitter to provide a dual light path for viewing of an object so that one optical path is provided for each eye.
FIG. 1 shows a cross sectional view of a typical stereomicroscope 100. The stereomicroscope 100 comprises a housing 101. A single objective lens 102 is provided for focusing the light reflected from a target 103 onto a plurality of prisms 104 and 105, through separate paths to enable a binocular vision through eye pieces 106 and 107 mounted on the housing 101.
The single objective 102 feeds the light into a distinct lens pathway comprising of an arrangement of plurality of prisms and lenses 104 and 105 two separate paths referred to hereinafter as lens pathways (LP). The lens pathways are shown in FIG. 2. The light, from the illumination source 207, after reflecting from the target (not shown) is directed towards the objective 201. Further, the light travels through the left LP 203 and the right LP 205 before reaching the corresponding eyepiece. However, the Inter LP distance of the stereomicroscope described herein above is limited and fixed. The left LP and right LP, which lead to the right and the left eyepieces with optical images, are very close to each other, with a distance in the range of 22 millimeters to 26 millimeters to provide a stereo image. However, the average distance between the eyes of the human being is about 60 to 70 millimeters.
It is advantageous to have a stereomicroscope with a system for varying an inter-objective distance for increasing a depth of perception and a field of vision.
In the prior art microscopes that are available at present, the angle subtended between the Right Optical system and the Left Optical System at the target/object is fixed, limited and small. None of the currently available microscope has a facility for controlling the angle between the left optical system and the right optical system.
Hence, there is a need for a stereomicroscope with a variable inter-objective distance to provide an increased and variable depth of vision. Also there is a need to provide a stereo microscope with a system for controlling the angle subtended by the left optical system and the right optical system at a target as to increase a 3D effect and depth perception.
The above mentioned shortcomings, disadvantages and problems are addressed herein, which will be understood by reading the following specification.